The assessment was conducted on the lake eutrophication in the Dalian Lake ecological restoration region using Uarlson model and comprehensive trophic status index.The results revealed that the water at all monitoring sites are eutrophic and the main factors are nitrogen and phosphorous.The balance of nitrogen and phosphorous was poor with the total N input of 2174 kg/a,92% of the total N content,and the total P input of 466.27 kg/a,97%of the total P content,which mainly come from the upper-stream,while the out puts of N and P are 1963 and 352.1 kg/a,respectively,showing that the rates of retained N and P was 9% and 24%, respectively.Although the water quality of Dalian Lake ecological restoration region has been significantly improved,some measures still need to be taken to decrease the input of N and P from the upperstream in order to reach the standard ∏ of the surface water.